1. Field of the Invention
The present invention relates to an inkjet head operable to eject an ink onto a recording medium, for performing a printing operation on the recording medium.
2. Discussion of Related Art
U.S. Pat. No. 6,652,081 (corresponding to JP-2003-145791A) discloses an inkjet head unit including: (a) a front head unit having (a-1) a cavity plate unit (passage defining unit) having a plurality of inlets opening in an end portion of its upper surface, and (a-2) a piezoelectric actuator (actuator unit) superposed on the upper surface of the cavity plate unit with an adhesive sheet being interposed between the piezoelectric actuator and the cavity plate unit; and (b) an ink tank storing an ink that is to be supplied to the inlets of the cavity plate unit. In this inkjet head unit, a filter plate is fixed to the upper surface of the cavity plate unit so as to cover the inlets. On an upper surface of the filter plate, there are disposed a plurality of tubular sleeves which are held in communication with the respective inlets. Each of the tubular sleeves is fixed at one of its opposite end portions to the upper surface of the filter plate by means of epoxy resin as an adhesive, and is connected at the other end portion to the ink tank. The ink tank and the front head unit are thus held in communication with each other, so that the ink stored in the ink tank can be supplied to the front head unit.
However, in the inkjet head unit disclosed in the above-identified U.S. patent publication in which the plurality of tubular sleeves are disposed to be held in communication with the respective inlets such that each of the tubular sleeves is fixed at its end portion onto the filter plate by the epoxy resin, some of the epoxy resin interposed between the tubular sleeves and the filter plate could project to cover portions of the filter plates opposed to the respective inlets of the cavity plate unit, thereby filling pores of the filter plate.